I. Field of the Invention
The present invention relates generally to multi-row, wide-swath, agricultural implements such as chemical applicator implements having a laterally folding toolbar mounted to a towable carriage. More specifically the present invention includes a multi-section toolbar that folds rearward alongside a trailing carriage so as to reduce the overall transport dimensions of the implement.
II. Description of the Prior Art
Agricultural semi-trailed equipment such as, for example, chemical application equipment is used to treat a relatively wide swath of a field in a single pass. A chemical applicator generally consists of a rolling carriage that supports a vessel to carry application material and a toolbar suspended from the carriage framework. The carriage is attached to a prime mover, normally a tractor, through a load bearing pivot point at the rear of the prime mover which allows the tractor-trailer combination to articulate for steering purposes. Tools such as rolling coulters along with injection nozzles or knives are attached to the toolbar to accurately incorporate plant nutrients into the soil at desired depths and lateral increments measured from the centerline of the main carriage frame and the prime mover.
The economics of multi-row processing of chemical incorporators continuously push for increasing the latitudinal or lateral distance covered by a toolbar, commonly known as swath width, of the application equipment in an effort to reduce the number of passes required for a given area of land. In addition to increasing the toolbar's swath width, larger chemical reservoir capacities are also desired to reduce the number of time consuming reloading operations that are required. As the lengths of applicator toolbars are increased they must also have sufficient folding capabilities to collapse the overall width of the device for towing the applicator safely down a road. For narrower road transport, the conventional wide swatch toolbar is provided with a rigid center section approximately the width of the maximum overall transport dimension and multiple wing sections suspended from the center section that fold out from the center section. It is often desirable that the multiple stages of wing folds match the standard incremental swath width of the corresponding planting equipment so as to enhance the toolbar's versatility. Suspending the wings laterally from the center section eliminates the need for a wheel lift assembly to carry the wing sections in the raised position thereby reducing the amount of crop damage that can occur while turning at the row ends.
To further enhance producer profitability with chemical applicators it is also desirable to minimize the lateral deviation of nutrient placement relative to the plants as well as minimizing plant damage from the trailing carriage assembly caused by off-tracking. Off-tracking is a common characteristic of fixed axle semi-trailed equipment whenever the refraction angle at the hitch point deviates from an aligned position such as during turning or when steering corrections are necessary. Implement off-tracking is also exaggerated on trailing equipment when it is traversing a side slope where gravitational force tends to pull or slide the trailer down the slope causing the centerline of the implement to deviate from the center line of the prime mover. Whatever the cause for off-tracking the result is a substantial risk of increased crop damage and yield loss whenever a fertilizer applicator deviates from the center of the crop swath.
Off-tracking has been minimized previously by keeping the incorporation toolbar as close to the prime mover as possible. This means that the toolbar is often coupled to the carriage as far forward as possible, typically in a mid mounted position between the forward most wheels of the rolling carriage and the rear wheels of the prime mover. A mid-mount toolbar design generally requires the center section of the toolbar to transverse beneath the carriage hitch that is fastened to the drawbar of the prime mover.
To further reduce costly crop damage while turning at the row ends, the minimum toolbar lift height, measured from the ground to the lowest point of the toolbar's incorporation tool, should exceed the height of the crop to which the fertilizer is being applied. However, on mid mounted toolbars the lift height of a mid mounted toolbar is restricted by the height of the carriage hitch. This lift height is further diminished on successive wing sections relative to the center section due to the gravitational and inertial forces that cause wings to sag or dip when the applicator is turned around on the row ends. To enhance the lift height of the toolbar during such turns it is a common industry practice is to slightly elevate or pivot the outer wings up. This method of raising the outer wings works relatively well with prior mid-mounted toolbars because the wings are generally pivotally secured about a horizontal axis and the method of slightly lifting the wings on the end rows is similar to folding the wing for applicator transport.
However, a major problem associated with the conventional vertical folding toolbars is the excessive height of the folded wings in the transport position which thereby increases the possibility of striking overhead obstacles during road transport.
A further problem associated with prior folding toolbars is that during field incorporation they do not have sufficient vertical travel laterally among the toolbar sections to compensate for rolling terrain such as hills, draws, or terraces.